[vsnet-grb-info 21019] GRB 180809A: CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23117
SUBJECT: GRB 180809A: CALET Gamma-Ray Burst Monitor detection
DATE:    18/08/10 12:55:19 GMT
FROM:    Valentin Pal'shin at AGU  <val at phys.aoyama.ac.jp>

S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, V. Pal'shin,
S. Sugita, Y. Kawakubo, A. Tezuka, S. Matsukawa, H. Onozawa,
T. Ito, H. Morita, Y. Sone (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
W. Ishizaki (ICRR), M. L. Cherry (LSU),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The GRB 180809A (MAXI/GSC detection: Yatabe et al., GCN Circ. 23103;
Fermi-GBM trigger #555507497) was detected in ground analysis
of the CALET Gamma-ray Burst Monitor (CGBM) data near the MAXI trigger
time at T0=11:38:25 UT on 9 August 2018.
The burst signal was seen by all CGBM detectors.

The burst light curve shows a weak pulse which starts
at T-15.1 sec and ends at T-4.2 sec.
The T90 and the T50 durations measured by the SGM data are
10.0 +- 1.6 sec and 5.0 +- 1.6 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1217849910/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.